20_1/2x25_1/2x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Ventilation Expanded size: 4" x 4"

Expanded size: 4" x 4" x 4"

ePAR Efficacy: 2

Laboratory etc

Dimming Settings: 660x2

use a well aerated organic-based growing medium amended with a source of time released (N) nitrogen such as manure based compost

20_1/2x25_1/2x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Ventilation Expanded size: 4" x 4"Nordic Pure Custom MERV 13 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition